1. Technical Field
The present disclosure relates to the technical field of liquid crystal displays (LCDs), and more particularly, to an LCD panel and a pixel electrode thereof.
2. Description of Related Art
Nowadays, LCDs have been widely used in various electronic devices such as mobile phones, personal digital assistants (PDAs), digital cameras, computer monitors and notebook computers. An LCD generally comprises a backlight module and an LCD panel. The LCD panel is comprised of two substrates and a liquid crystal layer filled therebetween. During the manufacturing process of the LCD panel, an alignment film is usually formed on each of the two substrates to align liquid crystal molecules into a specific orientation.
Currently, there is a technology for forming an alignment film which is called PSVA (polymer stabilization vertical-alignment) technology. According to the PSVA technology, a monomer compound is incorporated at an appropriate concentration into the liquid crystal material and then the liquid crystal mixture is shaken to a homogeneous state. Then, the liquid crystal mixture is heated by a heater until the liquid crystal mixture reaches an isotropic state. After the liquid crystal mixture cools down to the room temperature, it reverts to a nematic state. Afterwards, the liquid crystal mixture is filled into a cell and a voltage is applied. When the liquid crystal molecules become stably aligned under the action of the voltage applied, the monomer compound is polymerized through illumination of ultraviolet (UV) rays or through heating to form a polymer layer, thus achieving the purpose of stable alignment.
Usually, in a PSVA type LCD panel, an alignment slit is formed in each pixel electrode of the pixel structure to align the liquid crystal molecules into a specific orientation. Referring to FIG. 1, there is shown a schematic view of a portion of the PSVA type LCD panel corresponding to a pixel. As shown in FIG. 1, the LCD panel comprises a pixel region 1 and a pixel electrode 2 located in the pixel region 1. The pixel electrode 2 comprises a peripheral portion 21 and a plurality of branch portions 22 located inside the peripheral portion 21. A cruciform opening 23 is formed at a center of the branch portions 22 to form a central backbone of the pixel electrode 2 and divide the branch portions 22 into four regions. Each of the regions consists of branch portions 22 disposed flat and obliquely at an angle of 45°.
In the aforesaid pixel electrode structure, the orientations of the central backbone of the pixel electrode 2 are parallel with or perpendicular to the absorption axle of 0/90° VA polarizers. Therefore, when a voltage is applied to the pixel electrode 2, the cruciform central backbone presents a dark state in the pixel region 1, which decreases the transmission ratio of the backlight.